Synthesis of ZnO Nanostructure by Sol-Gel Spin Coating Method

In this study, we use spinning methods to coat glass slides with sol-gel ZnO thin films, composed of zinc acetatedihydrate, monoethanolamine (MEA), 2-Methoxethanol. The effect of the annealing temperature on the structural morphology and optical properties of these films was investigated. These ZnO films were preheated at 100 oC for 10 min and annealed at 350, 500 and 550 ˚C for 60 min. As-deposited films, formed by amorphous zinc oxide-acetate submicron particles, are transformed into a highly-oriented ZnO after thermal treatment. The surface morphology, phase structure and optical properties of the thin films were investigated by scanning electron microscopy (SEM), atomic force microscopy (AFM), X-ray diffraction (XRD) and optical transmittance. Both techniques produced nanostructured ZnO thin films with well-defined orientation. The annealed films were transparent in the visible range with an absorption edge at about 375 nm and a transmittance of 80% with an average diameter of 40 nm. XRD results show the film was composed of polycrystalline wurtzite, with a preferential c-axis orientation of (002) and a single sharp XRD peak at 34.40, corresponding to the hexagonal ZnO. The grain size with increasing the annealing temperature.